This invention relates generally to dry break disconnect couplings for the transfer of liquids and gases in applications where quick attachment and detachment are required without loss of the medium being transferred. More particularly, this invention relates to fueling nozzles and valves for supplying fuel to aircraft fuel tanks of the type having a refueling adapter accessible from below the wing of an aircraft. Still more particularly, this invention relates to jet aircraft refueling nozzles or couplings that connect to a standard refueling adapter generally mounted inside the lower wing surface of the aircraft. The invention also relates to couplings and nozzles which connect to a fuel source which is generally below the surface of the ground.
In aircraft refueling operations, it is desirable that the nozzle be light in weight and easy to handle because of the weight of the hose and typical distances from the refueling adapters to the ground. Most refueling nozzles presently in use are excessively heavy and long, which makes such nozzles difficult to handle and causes excessive loads on the aircraft adapter when the end of the nozzle farthest from the adapter is subjected to side loads.
Most prior art aircraft refueling nozzles have the additional disadvantage that it is difficult to radially position them for connection to the aircraft with and without fuel pressure in the fuel line connected to the refueling nozzle.
In a typical application, a service vehicle is connected to the refueling hose to pump fuel into the aircraft fuel tanks. If by mistake the refueling nozzle were left connected to the aircraft adapter and the operator of the service vehicle attempted to drive the service vehicle away from the aircraft, the nozzle would separate from the aircraft, generally causing damage to both the aircraft and the servicing equipment. Such incidents often damage the aircraft refueling adapter so severely that fuel spills result; and the aircraft is removed from service for costly, time-consuming repairs. Attempting to drive the service vehicle away while the refueling nozzle is connected to the aircraft also often damages the refueling nozzle, requiring replacement or repair at great expense and inconvenience.
Therefore, there is a need in the art for a relatively short, lightweight aircraft refueling nozzle, which includes a mechanical fuse which causes the nozzle to break away from the aircraft refueling adapter upon the application of predetermined axial loads and side loads, which is easy to position with pressure in the line for connection to the aircraft and which is easy to reassemble after a separation of the mechanical fuse occurs and which in addition provides convenient modular accessories.